201221120021021 has 8 divisors (see below), whose sum is σ = 205114042714680. Its totient is φ = 197331763912192.

The previous prime is 201221120021017. The next prime is 201221120021023. The reversal of 201221120021021 is 120120021122102.

It can be written as a sum of positive squares in 4 ways, for example, as 43378833960121 + 157842286060900 = 6586261^2 + 12563530^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 201221120021021 - 2² = 201221120021017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221120021023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 891532280 + ... + 891757953.

It is an arithmetic number, because the mean of its divisors is an integer number (25639255339335).

Almost surely, 2^{201221120021021} is an apocalyptic number.

It is an amenable number.

201221120021021 is a deficient number, since it is larger than the sum of its proper divisors (3892922693659).

201221120021021 is a wasteful number, since it uses less digits than its factorization.

201221120021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1783292415.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 201221120021021 its reverse (120120021122102), we get a palindrome (321341141143123).

The spelling of 201221120021021 in words is "two hundred one trillion, two hundred twenty-one billion, one hundred twenty million, twenty-one thousand, twenty-one".